The IEEE 802.16 standard specifies a fixed and mobile Broadband Wireless Access (BWA) standard for a wireless Metropolitan Area Network (MAN). The IEEE 802.16 standard defines different physical layer technologies for different frequency bands.
In current communication systems, multicast and broadcast techniques are employed for transmitting data from one source to multiple destinations. In order to effectively utilize radio resources, the IEEE 802.16e standard has introduced the Multicast and Broadcast Service (MBS) that standardizes the point to multi-point transmission in the mobile network. The MBS service may support not only the multicast and broadcast of low bit-rate message services such as text, but also the multicast and broadcast of high bit-rate multimedia services.
Layered coding is a data representation technique in which the source data is partitioned into multiple layers. The layers are organized normally in a way that the lowest layer also called base layer contains the minimum information for intelligibility; the other layers also called enhancement layers contain additional information that incrementally improves the overall quality of the source data. When the layered coding technique is applied in a video codec, the video data is normally encoded into multiple layers including a base layer of comparatively low quality video and at least one enhancement layer of increasingly higher quality video. At the receiver side of a layered coding communication system, a decoder can be configured to choose to decode a particular subset of these layers to get a particular quality of the video according to its preference and decoding capability.
Adaptive MCS (Modulation and Coding Scheme) is a key feature for WiMAX technology, wherein a higher level of MCS is employed in the area of good Signal to Noise Ratio (SNR); on the contrary, in the area of poor SNR, a relatively lower level of MCS is employed to guarantee the connection quality and link stability. In the MCS supported by the WiMAX, there are three categories of modulation types: QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation) and 64QAM.
To implement the adaptive MCS, one of important requirements is to acquire accurate feedback report of channel quality from the Mobile Stations (MS). Two kinds of mechanisms are defined in the standard for the MS to report the DL (Download Link) CINR (Carrier to Interference and Noise Ratio) value to the Base Station (BS):                the first one is REP-RSP (Channel measurement Report-Response) MAC message. The REP-RSP message in response to a REP-REQ message from the BS shall be sent by the MS to report estimation of the DL physical CINR or the effective CINR;        the second one is periodic CINR report with fast-feedback (CQICH) channel, wherein the BS may allocate a CQICH sub channel using a CQICH Control Information Element to provide a unicast uplink opportunity for periodic CINR reports (physical CINR or effective CINR), and the MS transmits channel quality information on the assigned CQICH of every frame.        
The reporting messages sent by the MSs will cause a certain amount of signaling overhead as a function of the frequency of the polling and the total number of subscribers. Therefore, it is desirable to provide a method for reporting state information with a smaller signaling overhead.